[nudony]

From a female perspective (yes I've actually asked the question) it actually feels good for many women to sit - at least temporarily - spread eagle because it essentially stretches and opens up the labia. That feeling I guess would be comparable to an uncircumcised guy pulling up his foreskin; since it is a sensitive area...well it just feels nice.

Most nudist women opt not to stay or go that way because, as one lady once put it, they don't want anyone/everyone "looking up their ass." As you put it; some don't care, while others are amused by it. My ex didn't care, and I think everyone at our resort has seen her labia at some point. I didn't care myself; and most men at the resort are respectful enough, even if they do look - which is quite natural (and if you think nudist women don't check out penis, think again) - to not just blatantly stare.